Our collaborators in the Jaffrey laboratory at Cornell and in the Unrau laboratory at Simon Fraser had previously reported the development of the fluorescent RNA modules called 'Spinach' and 'RNA Mango', rsepectively, but further improvement was hampered by a complete lack of knowledge of its structural and biophysical basis of function. In 2014, we determined the structure of Spinach, revealing an unprecedented mode of RNA-fluorophore interaction, which relies on a G-quadruplex motif. To further the application of this kind of fluorogenic RNAs in vivo, we have started to analyze the mechanism of action of G-quadruplex-specific helicase proteins.